Zigzag sewing machine



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ZIGZAG SEWING MACHINE Filed May 25, 1939 3 Sheets-Sheet 1 I n i o Sept. 29, 1942. w. BOLTER Y 2,297,197

zmzm smwme mourns Filed May 25, 1939 3 Sheets-Sheet 2 Sept. 29, 1942. w. BGLTER 2,297,197

Z'IGZAG SEWING MACHINE Filed May 25, 1959- s Sheets-Sheet 3 my ll.\

Patented Sept. 29, 1942 ZIGZAG SEWING MACHINE Wilhelm Biilter, Karlsruhe, Germany; vested in the Alien Property Custodian Application May 25, 1939, Serial No. 275,737

r Germany May 31, 1938 9 Claims. (01. 112-158) This invention relates toa household or domestic machine of the character wherein the sewing stitches are arranged in zigzag-fashion across the median line of stitches.

, In many instances, sewing machines of this character have a device wherein each set of stitches, measured longitudinally of the stitch line, varies from wide central stitches of the set to narrow stitches at the ends of the set.

Certain machines are arranged for the narrow I stitch portions to be positioned to the left or right sides of the maximum width of stitch and also to be arranged centrally thereof. In order to accomplish this disposition of the stitches, certain shifting means for the needle frame are used.

One object of the present invention is to provide a novel form of means for shifting the needle frame, as will be hereinafter set forth.

A second important object of the invention is to provide a device of this kind wherein the main shaft of the machine head serves to drive an oscillating member suitably connected to the needle frame to actuate the same.

'A third important object of the invention is to provide means whereby the oscillating member may be adjusted to regulate the extent of the oscillation of the needle, frame relative to the normal line of stitching.

Under normal circumstances, it is rather difficult to obtain this shifting function during the operation of the machine, but in my invention,

arrangement is made whereby the shifting may be effected during the usual operation of the machine.

A fifth important object of the invention is to acters denote corresponding parts in the several views, and in which Figure 1 illustrates the front elevation of the operative parts of a machine constructed in accordance with this invention, certain of the parts being shown in section in order to disclose those within the machine head;

Figure2 illustrates a plan view of the machine shown in Figure 1, also having certain of the parts in section for the-purpose of showing operative devices within the machine head;

Figure 3 illustrates a detail elevation showing the needle supporting frame adjusted so that all stitches lie equally on both sides of the normal stitch path;

Figure 4 illustrates a view similar to Figure 3 but showing the frame adjusted to throw the narrower stitches to the left'of the normal stitch path;

Figure 5 illustrates a view similar to Figure 4 but showing the frame adjusted to throw stitches of smaller scope to the right of the normal needle path;

Figure 6 illustrates an enlarged detail view showing the device for laterally oscillating the stitch member to theright of the normal needle Path;

Figure 7 illustrates a section on the line 7-1 of Figure 6;

Figure 8 illustrates an enlarged fragmentary view showing the means for shifting the needle path to one side or the other of its normal position;

Figure 9 illustrates a cross sectional view of the parts shown in Figure 8 and certain other parts, the view being taken at right angles to Figure 8;

Figure 10 illustrates a view similar to Figure 6 but showing a slight modification thereof Figure 11 illustrates a view similar to Figure 8 but showing the means for adjusting the oscillating member toregulate the extent of the oscillations of the needle frame;

Figure '12 illustrates a detail section on th line i2-i2 of Figure 13;

Figure 13 illustrates a section on the line l3--i 3 of Figure 12; a

Figure 14 illustrates a section on the line M-M of Figure 11; and

Figure 15 illustrates a face view of the adjusting device used in connection with Figure 11 and showing the same partly broken away.

In the construction of this machine, there is provided the usual stand'or other support having suitable driving means for driving the entire apparatus. On this stand is mounted a substantially L-shaped head I, the stand being provided with a plate 2 for supportin this head. Extending through the hollow head i is a crank shaft 3 supported in suitable bearings as indicated at at and 3b. On the shaft 3 is fixed a crank member :8 which is connected by a link 5 to an adjustable head 6 mounted on a needle bar 8 for selective bar 8 is supported in a guide frame I having an oscillatable floor end, the upper end being fixed by a carrier or head member 9 which engages in a socket member I at the upper end of the frame I. This member 9 is mounted on a transverse pivot carried by the machine head I.

Below the plate 2 is journalled a horizontal shaft l2 which is connected to the shaft 3 by a pitman |2a engaging a crank |2b on the shaft 3. Thus, the rotation of the shaft 3 actuates the shaft l2 in the usual manner. Furthermore, the shaft |2 actuates the lower stitch forming mechanism I3 which is of the ordinary construction and is not deemed necessary here further to be described.

In order to regulate the oscillation of the frame 1 there is provided in the head a transverse shaft |5 which is supported at one end in a bore I6 formed in the head I and at its other end in Thereby the shaft I5 is rotated when the shaft 3 rotates. The gear ratio between the shafts 3 and I5 is such that the shaft 3 rotates twice in order to cause the rotation once of the shaft IS.

The connection between the swinging frame I and the eccentric I4 is quite similar to that commonly used in a Stephenson reversing gear. Thus, the eccentric I4 is engaged between the arms of a fork 2| mounted on an oscillating lever 22 which i provided with a hub 21 fixed upon a rock-shaft 25 and secured in adjusted relation thereon by means of a set-screw 28. The head I is provided with a journal member or journal supporting member la, wherein is mounted a bushing 23 supporting theshaft 25 and secured in the journal Ia by means of a set screw 24. On this shaft 25 is carried an oscillating lever 26 and a guide segment 3| is provided with a journal 29 which fits in a suitable bore in the outer end of the lever 26, this guide segment being thus mounted for oscillation relative to said lever. A

screw 32 holds the journal in position relative to said arm. The guide segment 3| has mounted therein a slide 34 so that this slide may move from one end of the guide 3| to the other by proper adjustment thereof. The slide 34 carries a bolt 35 whereon is pivoted one end of a link 38 having its other end connected at 42 to the member I. Also, there is provided on the bolt 35 an adjusting rod 31. justing rod and the link head 36 to the slide. The link head is connected to the link 39 by means of a pair of screws 4|.

Furthermore, member la has mounted thereon an eccentric bolt 44 rotatable by means of a screw 50 which, when loosened, permits rotation of the journal 43 and when screwed up prevents rotation thereof. The screw 45 is eccentrically mounted on the member 44 and on this screw is mounted a lever 46 forming an adjusting member. The adjusting lever 46 carries a stop member 41 adapted to engage selectively in openings "11 so that the position of the lever 46 may be shifted and, when shifted, may be held by the engagement of the member 41 in a selected hole 41a.

Referring to Figure 8. it will be seen that the guide 3| oscillates about a fixed point, that is the axis of the shaft 25 while the member 36 may be shifted bodily upwardly and downwardly with A screw 38 holds both the adrespect to the guide member 3|. Obviously, if the screw 38 in its lowermost position coincides with the fixed point of oscillation, then there will be no longitudinal movement of the link 39. Furthermore, if the link 39 is above the point of oscillation of the member 3|, the oscillation will take place in accordance with an oscillatory movement.

In accordance with the foregoing, when the paths are positioned as in Figure 3, the oscillatory movement will be equal on both sides of the center line; when they are positioned as in Figure 4, the oscillatory movement will be such as to bring the shorter zigzag stitches on .the left side of the center line of the normal needle movement, and further, when positioned as in Figure 5, they will be positioned to bring the smaller or shorter zigzag stitches on the right side of the normal center line of the needle operation. I It is to be observed that the link '48 connects to the member 46 by the pivot 49, while it also connects to the guide 8| by the pivot 5|. Furthermore, at each end of the guide 3| is a stop, these stops being indicated respectively at 53 and 54.

In the form of the invention shown in Figure 10, the member 46 is replaced by member 46 whereon is formed an arm 46a having therein a cam curve or slot 46b. In this curve or slot 46b slides a pin 55 which supports the arcuate slide 3|.

In order to vertically adjust the member 36, the arm 31 has at its upper end a pivot 66 which is carried by a rock-arm 6| pivotally mounted on a pin 63. Secured to the arm 6| to move therewith is a segment 62 which depends from the pivot 63.

The pivot 63 is fixed on a plate 64 suitably supported from the head I, a boss 65 being provided .on the plate 64 to receive said screw 63. A pin 62a serves to fixedly connect the lever 6| with the segment 62. on the plate 64 is a second boss 68 wherein is engaged a stub-shaft or bolt 69. A segmental pinion II is mounted on the stubshaft 69 by means of a hub 69a and is held thereon by a screw 12, as best seen in Figure 12. This segmental pinion engages the segment 62. A spring 12a is interposed between the hub 69a and the boss 68 to hold the pinion frictionally against accidental movement. Screws 13 secure a stop arm or member 14 ,to the pinion ll. From the member [4 extends a stop-lug 15 having a pointed outer end. At 16 is a leaf spring having a notched portion ll wherein the point of the arm I5 may engage when the latter is turned in position. A covering cap I9 is secured to the plate 64 by means of screws 18. Carried by this cap 19 is a pair of oppositely disposed bosses and 88a wherethrough are screwed adjusting screws 8| and 82 which lie in the path of the member 15 so that by adjusting the screws 8| and 82, the throw of the member 15 may be regulated. That is to say, if the screw 8| be screwed in and the screw 82 be screwed out, as in Figure 15, then the arm 15 cannot rotate as far to the right a if the opposite conditions prevailed. Furthermore, by screwing the screws 8| and 82 toward each other, the motion of the arm 15 is limited, while when screwing them apart from each other, the motion of the arm 15 is permitted to increase. An adjusting lever 83 is mounted on the cylindrical boss 63a to rotate with the segmental pinion. At the free end of this adjusting lever there is provided. a handle member 86 and a pointer 81 which traverses a scale 88 supported on .the cap member 18 so that by moving the handle 86 from one position to another on the the link 39 is reciprocated to oscillate the member I in such manner that when the guide segment 3| of the gear is in one position adjusted by movement of the lever 46, the stitching will be formed as in Figure 3, this being the central position, while in either of the end positions, the stitching will be formed as shown in Figure 4 or in Figure 5, depending in which position the member M is located.

Furthermore, it will be seen that the position of the slide in the arcuate member will be regulated by movement of the wlever 3i which, in turn, can be regulated by the apparatus shown in Figures 11 to 15.

There has thus been provided a simple and efficient device of the kind described and forthe purpose specified.

It is obvious that changes may be made in the form and construction of the invention without departing from the material principles thereof. It is not therefore desired to confine the invention to the exact forms herein shown and described but it is desired to include all forms which properly come within the scope of the appended claims.

I claim: 1

1. In a stitch control for zigzag sewing machines for' household purposes, an oscillatory guiding means, a slide movable along said guide, a swinging lever, a fixed member whereon said lever is pivoted, means connecting the lever and guide .to rock the guide laterally upon movement of the lever, means adjustably supporting said said oscillating means, and means connecting the drive shaft and oscillating means and con- "stituting -a link motion device, said means in"- cluding a slide, a link connecting said slide and the free end of the oscillating .nreans, a guide member supporting said slide and'wherein the slide is longitudinally movable, means for rocking said guide member, means for shifting the slide longitudinally of the guide member,

means for indicating the position of the slide in the guide member, a plate supported from the head of the machine, an adjusting rod connected to the guide member to shift the posi-v tion thereof, means for actuating said rod supported from said plate, said plate having a slot therein and the adjusting rod being positioned behind the plate, said last means including a rock arm extending through the slot in said plate and having connection with said rod and, an

actuating member in front of said plate, and

means for indicating the position of said slide in said member carried by said plate.

6. In a sewing machine, a needle bar, oscillating means for supporting said needle bar, a

slide whereby the slide may be slidably adjusted in the guiding means for the purpose of adjusting the size of the zigzag stitch, an adjustment lever, a rotatable member whereon said adjustment lever is eccentrically pivoted, and means connecting the adjustment lever and guide, and a link pivotally connected at its respective ends to the adjustment lever and guiding means whereby the pivotal connection of the link and guiding member lies in the axis of swing of said guiding member when the latter is in neutral position.

2. Zigzag sewing machine in accordance with claim 1, characterized in that the link is mounted and laterally guided between and by the swinging lever carrying the guide member and by this guide member itself.

3. Zigzag sewing machine in accordance wit claim 1, in which the adjusting lever is mounted eccentrically on a .bolt, and means for axially and radially adjusting said bolt.

4. Zigzag sewing machine in accordance with claim 1, in which a guide cam slot is formed in the adjusting lever and serves as a connecting means for the adjusting lever and the guiding member, there being a journal mounted on said guiding member and engaging said cam slot.

5. In a sewing machine, a needle bar, oscillating means for supporting'said needle bar, a drive shaft for reciprocating the needle bar in drive shaft for reciprocating the needle bar in said oscillating means; and means connecting the drive shaft and oscillating means and constituting a link motion device, said means in-' cluding a slide, a link connecting said slide and the free end of the oscillating means, a guide member supporting said slide and wherein the slide is longitudinally movable, means for rocking said guide member, means for shifting the slide longitudinally of the guide member, means for indicating the position of the slide in the guide member, a plate supported from the head of the machine, an adjusting rod connected to the guide member to shift the position thereof, means for actuating said rod supported from said plate, said plate having a slot therein and the adjusting rod being positioned behind the plate, said last means including a rock arm extending through the slot in said plate and having connection with said rod and an actuating member in front of said plate, said last means further including a pin fixed on said plate, a lever arm mounted on said pin and connected to said adjusting rod, a gear segment fixed to the lever arm, a segment meshing with the first segment, and means for rotating said second segment including a finger piece in front of said plate.

7. The sewing machine of claim 6 characterizedby the plate having acam slot therein and having the lever arm provided on its free end with a guide member engaging in said cam s 0t.

8. The sewing machine of claim 6 characterized by having a stop member fixed to the second segment and by having a leaf spring .supported by said plate and having a notch engageable by said stop member in one position thereof.

9. The sewing machine of claim 6 characterized by having a stop member fixed to the second segment and by having a leaf spring supported by said plate and having a notch engageable by said stop member in one position thereof, said machine being further characterized by the plate having a cam slot therein and having the lever arm provided on its free end with a guide member engaging in said cam slot.

' WILHELM BoL'rER. 

